我有一台5 UITableViewCells
的UITableView
。每个单元格都包含一个UIButton
,其设置如下:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *identifier = @"identifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
cell = [[UITableView alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
[cell autorelelase];
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 5, 40, 20)];
[button addTarget:self action:@selector(buttonPressedAction:) forControlEvents:UIControlEventTouchUpInside];
[button setTag:1];
[cell.contentView addSubview:button];
[button release];
}
UIButton *button = (UIButton *)[cell viewWithTag:1];
[button setTitle:@"Edit" forState:UIControlStateNormal];
return cell;
}
我的问题是:在buttonPressedAction:
方法中,我如何知道哪个按钮被按下了。我考虑过使用标签,但我不确定这是不是最好的路线。我希望能够以某种方式将indexPath
标记到控件上。
- (void)buttonPressedAction:(id)sender
{
UIButton *button = (UIButton *)sender;
// how do I know which button sent this message?
// processing button press for this row requires an indexPath.
}
执行此操作的标准方法是什么?
编辑:
我已经通过下面的操作解决了这个问题。我仍然想知道这是不是标准的方法,还是有更好的方法?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *identifier = @"identifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier];
if (cell == nil) {
cell = [[UITableView alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier];
[cell autorelelase];
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 5, 40, 20)];
[button addTarget:self action:@selector(buttonPressedAction:) forControlEvents:UIControlEventTouchUpInside];
[cell.contentView addSubview:button];
[button release];
}
UIButton *button = (UIButton *)[cell.contentView.subviews objectAtIndex:0];
[button setTag:indexPath.row];
[button setTitle:@"Edit" forState:UIControlStateNormal];
return cell;
}
- (void)buttonPressedAction:(id)sender
{
UIButton *button = (UIButton *)sender;
int row = button.tag;
}
需要注意的是,我不能在创建单元时设置标记,因为单元可能会被出队。感觉很脏。一定有更好的办法。
发布于 2018-08-08 05:46:33
使用Swift 4.2和iOS 12,您可以选择以下完整示例中的5之一来解决您的问题。
#1.使用UIView
的convert(_:to:)
和UITableView
的indexPathForRow(at:)
import UIKit
private class CustomCell: UITableViewCell {
let button = UIButton(type: .system)
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
button.setTitle("Tap", for: .normal)
contentView.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
button.centerXAnchor.constraint(equalTo: contentView.centerXAnchor).isActive = true
button.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
button.topAnchor.constraint(equalToSystemSpacingBelow: contentView.topAnchor, multiplier: 1).isActive = true
button.leadingAnchor.constraint(greaterThanOrEqualToSystemSpacingAfter: contentView.leadingAnchor, multiplier: 1).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
import UIKit
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
cell.button.addTarget(self, action: #selector(customCellButtonTapped), for: .touchUpInside)
return cell
}
@objc func customCellButtonTapped(_ sender: UIButton) {
let point = sender.convert(CGPoint.zero, to: tableView)
guard let indexPath = tableView.indexPathForRow(at: point) else { return }
print(indexPath)
}
}
#2.使用UIView
的convert(_:to:)
和UITableView
的indexPathForRow(at:)
(可供选择)
这是上一个示例的替代方法,在上面的示例中,我们将nil
传递给addTarget(_:action:for:)
中的target
参数。这样,如果第一个响应器没有实现该操作,它将被发送到响应器链中的下一个响应器,直到找到正确的实现。
import UIKit
private class CustomCell: UITableViewCell {
let button = UIButton(type: .system)
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
button.setTitle("Tap", for: .normal)
button.addTarget(nil, action: #selector(TableViewController.customCellButtonTapped), for: .touchUpInside)
contentView.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
button.centerXAnchor.constraint(equalTo: contentView.centerXAnchor).isActive = true
button.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
button.topAnchor.constraint(equalToSystemSpacingBelow: contentView.topAnchor, multiplier: 1).isActive = true
button.leadingAnchor.constraint(greaterThanOrEqualToSystemSpacingAfter: contentView.leadingAnchor, multiplier: 1).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
import UIKit
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
return cell
}
@objc func customCellButtonTapped(_ sender: UIButton) {
let point = sender.convert(CGPoint.zero, to: tableView)
guard let indexPath = tableView.indexPathForRow(at: point) else { return }
print(indexPath)
}
}
#3.使用UITableView
的indexPath(for:)
和委托模式
在本例中,我们将视图控制器设置为单元格的代理。当点击单元格的按钮时,它会触发对委托的相应方法的调用。
import UIKit
protocol CustomCellDelegate: AnyObject {
func customCellButtonTapped(_ customCell: CustomCell)
}
class CustomCell: UITableViewCell {
let button = UIButton(type: .system)
weak var delegate: CustomCellDelegate?
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
button.setTitle("Tap", for: .normal)
button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
contentView.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
button.centerXAnchor.constraint(equalTo: contentView.centerXAnchor).isActive = true
button.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
button.topAnchor.constraint(equalToSystemSpacingBelow: contentView.topAnchor, multiplier: 1).isActive = true
button.leadingAnchor.constraint(greaterThanOrEqualToSystemSpacingAfter: contentView.leadingAnchor, multiplier: 1).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
@objc func buttonTapped(sender: UIButton) {
delegate?.customCellButtonTapped(self)
}
}
import UIKit
class TableViewController: UITableViewController, CustomCellDelegate {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
cell.delegate = self
return cell
}
// MARK: - CustomCellDelegate
func customCellButtonTapped(_ customCell: CustomCell) {
guard let indexPath = tableView.indexPath(for: customCell) else { return }
print(indexPath)
}
}
#4.使用UITableView
的indexPath(for:)
和用于委托的闭包
这是上一个示例的替代方案,在上面的示例中,我们使用闭包而不是协议委托声明来处理按钮点击。
import UIKit
class CustomCell: UITableViewCell {
let button = UIButton(type: .system)
var buttontappedClosure: ((CustomCell) -> Void)?
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
button.setTitle("Tap", for: .normal)
button.addTarget(self, action: #selector(buttonTapped), for: .touchUpInside)
contentView.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
button.centerXAnchor.constraint(equalTo: contentView.centerXAnchor).isActive = true
button.centerYAnchor.constraint(equalTo: contentView.centerYAnchor).isActive = true
button.topAnchor.constraint(equalToSystemSpacingBelow: contentView.topAnchor, multiplier: 1).isActive = true
button.leadingAnchor.constraint(greaterThanOrEqualToSystemSpacingAfter: contentView.leadingAnchor, multiplier: 1).isActive = true
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
@objc func buttonTapped(sender: UIButton) {
buttontappedClosure?(self)
}
}
import UIKit
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
cell.buttontappedClosure = { [weak tableView] cell in
guard let indexPath = tableView?.indexPath(for: cell) else { return }
print(indexPath)
}
return cell
}
}
#5.使用UITableViewCell
的accessoryType
和UITableViewDelegate
的tableView(_:accessoryButtonTappedForRowWith:)
如果你的按钮是UITableViewCell
的标准附件控件,任何点击它都会触发对UITableViewDelegate
的tableView(_:accessoryButtonTappedForRowWith:)
的调用,允许你获得相关的索引路径。
import UIKit
private class CustomCell: UITableViewCell {
override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
accessoryType = .detailButton
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
import UIKit
class TableViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
tableView.register(CustomCell.self, forCellReuseIdentifier: "CustomCell")
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CustomCell", for: indexPath) as! CustomCell
return cell
}
override func tableView(_ tableView: UITableView, accessoryButtonTappedForRowWith indexPath: IndexPath) {
print(indexPath)
}
}
https://stackoverflow.com/questions/1802707
复制相似问题